1. Scale Fail
or, how I learned to stop worrying
and love the downtime

4. Downtime
is
Sexy

5. 1. Be Trendy

8. NO
Resource Monitoring
Performance Testing
Traffic Monitoring
Load Testing
Tuning Analysis

9. Let History Be Your Guide
● Was database to slow last time?
● The database is too slow this time.
● Did the network cards fry last time?
● They're frying this time.
● Did Apache choke on memory leaks last time?
● It's Apache this time.
● Fixed things by using queues at your last job?
● Then fix them with queues at this job!

10. Barn Door Troubleshooting

11. Parallel Programming
XY
SE
OT
N

12. Don't
Worry
About
It
Program-
X Y
ming
SE

13. How to Single-Thread
Your Code
● Locks, Locks, Locks!
● Ignore scope and memory address space
● Frequently-updated single-row table
● Master Control Server process
● Single Master Queue
● Blocking threads which wait while checking on
a remote data source

14. The Old Way: Caching
Connection Caching Pool App Web
Server Server
App Web
Object Cache
DB
HTTP Cache
Data Cache
Server Server
App Web
Server Server

15. The New Way: Direct2DB
Web
Server
Web
DB
HTTP Cache
Server
Web
Server

16. Easy to Scale
● Web servers
● Caches
● Shared-nothing hosts
● Simple App Servers
For Wimps!

17. Hard to Scale
● Databases
● Queues
● Shared Filesystems
● Web Frameworks
For Real Developers!

18. SPoF

19. Single Point of Failure
App Web
Server Server
UserDB
Task App Load Web Load
Manager Server Balancer Server Balancer
PageDB
App Web
Server Server

20. Cascading Failure
Web
Server
UserDB
Task App Load Web Load
Manager Server Balancer Server Balancer
PageDB
App Web
Server Server

21. Be Sexy:
Go Down!